<template>
	<view>
		<view v-if="isStatusBar" class="status-bar" :style="'height:'+statusBarHeight+'px'">
			<!-- 状态栏背景,设置为不透明 -->
		</view>
		<view v-if="isFixed && isOccupy" class="top-header" :style="'height:'+topHeight+'px'">
			<!-- 头部占位 -->
		</view>
		<view v-else-if="isStatusBar" class="top-header" :style="'height:'+statusBarHeight+'px'">
			<!-- 状态栏占位 -->
		</view>
		<!-- 头部	 -->
		<view class="nav-bar flex" :class="{ 'activeIsFixed': isFixed }" :style="getNavBarStyle">
			<view class="back flex" v-if="isBack" @click="back" :style="iconWH">
				<view class="iconfont icon-31fanhui1"></view>
			</view>
			<view class="left flex" v-else-if="!onlyCenter" @click="leftClick" :style="iconWH">
				<slot name="left"></slot>
			</view>
			<view class="center flex" :class="isOnlyCenter" :style="'height:'+navbarHeight+'px'">
				<slot></slot>
			</view>
			<view class="right flex" @click="rightClick" v-if="!onlyCenter" :style="iconWH">
				<slot name="right"></slot>
			</view>
		</view>
	</view>
</template>

<script>
	/**
	 * NavBar 自定义头部
	 * @description 头部组件，主要用于头部导航
	 * @property {Number, String} color 图标和文字颜色
	 * @property {String} isBack 是否显示返回按钮
	 * @property {Boolean} isFixed  是否固定顶部
	 * @property {Boolean} onlyCenter  是否只显示中间部分
	 * @property {String} bgColor  背景颜色
	 * @property {Number} opacity 背景透明度
	 * @property {Boolean} isOccupy 固定时默认占位
	 * @property {Boolean} isStatusBar 默认包含系统状态栏
	 * @property {Boolean} isSplitLine 头部分割线
	 * @property {String} splitLineColor 头部分割线颜色
	 * @property {Number} splitLineHeight 头部分割线高度
	 * @property {String} styleSelf 自定义样式
	 * @event {Function} back 返回
	 * @event {Function} leftClick 左侧点击事件
	 * @event {Function} rightClick 右侧点击事件
	 */
	export default {
		name: "Header",
		data() {
			return {
				// 状态栏高度
				statusBarHeight: 0,
				// 状态栏加头部高度
				topHeight: 0,
			};
		},
		props: {
			// 头部高度
			navbarHeight: {
				type: [Number, String],
				default: 42
			},
			// 显示返回按钮
			isBack: {
				type: [Boolean, String],
				default: false
			},
			// 是否固定定位
			isFixed: {
				type: [Boolean, String],
				default: true
			},
			// 是否只显示中间部分
			onlyCenter: {
				type: [Boolean, String],
				default: false
			},
			// 背景颜色
			bgColor: {
				type: String,
				default: ""
			},
			// 背景透明度
			opacity: {
				type: [Number, String],
				default: 1
			},
			// 固定时默认占位
			isOccupy: {
				type: [Boolean, String],
				default: true
			},
			// 默认包含系统状态栏
			isStatusBar: {
				type: [Boolean, String],
				default: true
			},
			// 头部分割线 
			isSplitLine: {
				type: [Boolean, String],
				default: true
			},
			// 头部分割线颜色
			splitLineColor: {
				type: String,
				default: "#CCCCCC"
			},
			// 头部分割线高度
			splitLineHeight: {
				type: [Number, String],
				default: 1
			},
			// 字体颜色
			color: {
				type: String,
				default: ""
			},
			// 自定义样式
			styleSelf: {
				type: String,
				default: () => {
					return ""
				}
			}
		},
		mounted() {
			this.getSystemInfo()
		},
		computed: {
			// 中间部分样式
			isOnlyCenter() {
				return this.onlyCenter ? 'onlyCenter' : ''
			},
			// 头部样式
			getNavBarStyle() {
				let splitLine = this.isSplitLine ?
					`border-bottom: ${Number(this.splitLineHeight)}px solid ${this.splitLineColor};` : "";
				let top = this.isFixed ? `top:${Number(this.statusBarHeight)}px;` : "";
				let bgColor = Number(this.opacity) === 0 ? "" : `background-color:${this.bgColor};`;

				return `height:${Number(this.navbarHeight)}px;
				line-height:${Number(this.navbarHeight)}px;
				background:rgba(255,255,255,${Number(this.opacity)});
				color:${this.color};
				${bgColor}${top}${splitLine}${this.styleSelf}`
			},
			iconWH() {
				return `width: ${this.navbarHeight}px;height: ${this.navbarHeight}px;`
			}
		},
		methods: {
			// 返回
			back() {
				uni.navigateBack()
			},
			rightClick() {
				this.$emit("rightClick")
			},
			leftClick() {
				this.$emit("leftClick")
			},
			//获取状态栏高度
			getSystemInfo() {
				uni.getSystemInfo({
					success: res => {
						console.log(res,'**************');
						this.statusBarHeight = res.statusBarHeight
						let navbar = this.navbarHeight
						// #ifdef MP-WEIXIN 
						// 胶囊居中
						const custom = wx.getMenuButtonBoundingClientRect()
						navbar = custom.height + (custom.top - res.statusBarHeight) * 2
						// #endif
						if (!this.isStatusBar) this.statusBarHeight = 0
						this.topHeight = this.statusBarHeight + navbar
					}
				})
			}
		}
	}
</script>

<style scoped>
	.flex {
		display: flex;
	}

	.status-bar {
		width: 100vw;
		position: fixed;
		top: 0;
		left: 0;
		right: 0;
		z-index: 9;
		background-color: #ffffff;
		opacity: 1
	}

	.nav-bar {
		font-size: 16px;
		width: 100vw;
	}

	.back,
	.left,
	.right {
		align-items: center;
		justify-content: center;
	}

	.center {
		flex: 1;
		align-items: center;
		justify-content: center;
	}


	.top-header {
		position: relative;
		top: 0;
		width: 100%;
	}

	.activeIsFixed {
		position: fixed;
		right: 0;
		left: 0;
		z-index: 99;
	}

	.activeBgColor {
		border: solid 1px transparent;
		background-image: linear-gradient(#ffffff, #ffffff),
			linear-gradient(to right, #FF007F 0%, #00A0E9 100%);
		border-radius: 25px;
		background-clip: content-box, border-box;
		background-origin: border-box;
	}

	.onlyCenter {
		margin: 0 10px;
	}
</style>